Add user invitations

app/Template/user_invite/show.php

@@ -0,0 +1,15 @@
+<div class="page-header">
+    <h2><?= t('Invite people') ?></h2>
+</div>
+<form method="post" action="<?= $this->url->href('UserInviteController', 'save') ?>" autocomplete="off">
+    <?= $this->form->csrf() ?>
+
+    <?= $this->form->label(t('Emails'), 'emails') ?>
+    <?= $this->form->textarea('emails', $values, $errors, array('required', 'autofocus')) ?>
+    <p class="form-help"><?= t('Enter one email address by line.') ?></p>
+
+    <?= $this->form->label(t('Add these people to this project'), 'project_id') ?>
+    <?= $this->form->select('project_id', $projects, $values, $errors) ?>
+
+    <?= $this->modal->submitButtons() ?>
+</form>